This invention relates to the method and apparatus for the manufacture of fiber reinforced structures.
State of the Art: It is desirable to have inexpensive, strong, lightweight, easily manufactured, dimensionally accurate components in a variety of sizes and geometries for use in aircraft and aerospace applications or any application where such structures are suited for use. However, meeting such criteria for components is difficult.
For example, the airframe of commercial aircraft is typically constructed of aluminum forgings, titanium forgings, aluminum sheet metal, and if desired, titanium sheet metal and is powered using turbofan type engines. High strength, low weight materials are used in the airframe in order to maximize the maneuverability of the aircraft, the responsiveness of the aircraft, the payload capacity of the aircraft, and the range of the aircraft. For instance, in commercial aircraft the main wing spar is typically a machined high strength aluminum forging extending most of the wing span of the aircraft including the fuselage in order to provide high strength and low weight to the wings of the aircraft and fuselage. In other instances, various portions of the wings and fuselage of an aircraft are fabricated from an aluminum sheet. As the wings and fuselage are formed of complex geometric shapes, it is difficult to fabricate sheet aluminum or sheet titanium into assemblies having high strength and low weight as the various portions of the assemblies are secured together through the use of fasteners which add weight to the assembly.
Similarly, where possible, high strength, low weight materials are used in the aircraft engines and the nacelles of an aircraft. For instance in a commercial aircraft, a turbofan type engine includes a ducted fan, a large diameter axial-flow multi-stage compressor, as the primary source of thrust by the engine while the gas generator portion of the engine provides a smaller amount of the engine""s thrust. The turbofan type engine being contained in an engine nacelle attached to the aircraft, typically, being attached to a portion of a wing or fuselage.
Since weight is of concern in aircraft engines and the nacelle containing the engine, it is desirable to provide the lightest engine and nacelle structure possible to meet the operational criteria for the aircraft while providing the required aircraft operational safety criteria. Typically, one of the desired operational safety characteristics for a turbofan aircraft engine is that if a fan blade, a compressor blade, or a turbine blade catastrophically fails during engine operation, the blade or pieces of the blade be contained or caught within either a portion of the engine housing or the nacelle. Typically, aircraft manufactures have required the fan housing be such a structure for the engine thereby making the fan housing one of the heaviest engine components. Accordingly, other portions of the nacelle are required to retain portions of compressor blades or turbine blades, if the engine structure itself, such as a compressor housing or turbine housing are not strong enough to retain the failed engine part.
The design of inexpensive, strong, lightweight, easily manufactured, dimensionally accurate nacelle components of sizes and geometries for use in aircraft is a formidable task. For instance, a fan housing must be strong enough to contain the energy of a fan blade when the failure occurs at maximum engine speed, must be dimensionally accurate over a range of engine operating conditions, must be easily manufactured at a reasonable cost, must be low weight, etc. Fan housings have been metal structures using a variety of reinforcing grids, typically formed of metal. However, such fan housings are expensive, difficult to manufacture, require extensive tooling to manufacture to close tolerances, and heavy.
In other instances, some fan housings have been composite type structures including metal components and non-metallic or organic type reinforcing components in an attempt to provide a high strength, low weight structure capable of containing a broken fan blade. However, such composite type structures are difficult to construct because the reinforcing structure of non-metallic materials for the fan housing has been difficult and expensive to construct. Other portions of the nacelle have complex geometric shapes to properly control the flow of air around the engine, wing, and fuselage making such components difficult to manufacture as metal assemblies.
Therefore, a need exists for a method and apparatus for the fabrication of composite structures for various aircraft components of the wings and fuselage to replace metal assemblies. Similarly, a need exists for a method and apparatus for fabrication of composite structures for aerospace vehicles and the like, Such methods and apparatus for the fabrication of composite structures for aircraft, or aerospace vehicles, or any application where low weight and high strength are required, must be capable of manufacturing an assembly that has structural integrity, reliability in operation, repeatability of manufacture, dimensional control of the structure, and a reasonable cost for the composite structure.
The present invention relates to the method and apparatus for the manufacture of fiber reinforced structures. The present invention includes the tooling and its use for the manufacture of reinforced structures. The present invention comprises a conformable locating aperture system (CLAS) used for the formation of composite structures.